GTG incident on 2011-02-24 — MI

Operator
Michigan Consolidated Gas Co (Michcon)
Cause
Material Failure Of Pipe Or Weld
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities 0 injuries
Property damage (nominal)
$79,507
Incident datetime
2011-02-24 12:57
Report number
Location
MI
Narrative
Leak discovered during routine facility checks by employees of operator and employees of another operator with facilities at same location. Potential likely causations (including failures in valve body bleed or grease/sealant line extension piping) investigated, but could not be confirmed. Decision made to isolate and reduce pressure in pipeline segment to allow further investigation. After isolating 2 adjacent valve sections and reducing pressure though flow to lower pressure system, impacted segment further isolated and remaining gas vented to atmosphere. Impacted segment was purged (gas to air) using air movers in anticipation of necessity to perform welding operations to complete repairs. Investigation through excavation revealed crack in 2 inch fillet weld at socket welded connection installed in 2007 as facility modification to allow liquid removal from low point in a non-piggable section of station piping. Ice from freezing of ground water in vicinity of leak (due to cooling of gas as a result of pressure reduction) impacted adjacent 2 inch piping (not related to siphon), prompting repairs to adjacent (nonleaking) 2 inch piping in addition to piping at location of leak. After repairs were completed and nondestructive inspections completed, line segment was purged (air to gas), pressurized and returned to normal operation.
Detailed record list
Report Received Date
2011-03-25 00:00:00
Iyear
2011
Report Number
20110033
Supplemental Number
15254
Report Type
Supplemental Final
Operator Id
Name
Michigan Consolidated Gas Co (Michcon)
Operator Street Address
One Energy Plaza
Operator City Name
Detroit
Operator State Abbreviation
MI
Operator Postal Code
48226
Local Datetime
2011-02-23 11:12:00
Location Latitude
Location Longitude
Nrc Rpt Num
Nrc Rpt Datetime
2011-02-24 14:10:00
Commodity Released Type
Natural Gas
Unintentional Release
6013
Intentional Release
5049
Accompanying Liquid
0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Shutdown Due Accident Ind
Yes
Shutdown Datetime
2011-02-25 12:00:00
Restart Datetime
2011-02-26 23:00:00
Ignite Ind
No
Explode Ind
No
Num Pub Evacuated
0
Incident Identified Datetime
2011-02-24 12:57:00
On Site Datetime
2011-02-24 12:57:00
On Off Shore
Onshore
Onshore State Abbreviation
Mi
Onshore Postal Code
48054
Onshore City Name
China
Onshore County Name
St. Clair
Designated Location
Milepost
Designated Name
59.00
Pipe Fac Name
Belle River Mills Compressor Station
Segment Name
36" Milford-Belle River Loop
Federal
No
Location Type
Operator-Controlled Property
Incident Area Type
Underground
Incident Area Subtype
Under Soil
Depth Of Cover
105
Crossing
No
Pipe Facility Type
Interstate
System Part Involved
Onshore Pipeline, Including Valve Sites
Item Involved
Weld/fusion, Including Heat-Affected Zone
Weld Subtype
Fillet Weld
Installation Year
2007
Material Involved
Carbon Steel
Release Type
Leak
Leak Type
Crack
Class Location Type
Class 2 Location
Could Be Hca
No
Pir Radius
52
Heat Damage Ind
No
Non Heat Damage Ind
No
Hca Fatalities Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
38500
Est Cost Intentional Release
32300
Est Cost Prop Damage
79507
Est Cost Emergency
0
Est Cost Other
0
Prpty
150307
Accident Psig
775
Mop Psig
1000
Mop Cfr Section
Not On Omb-Approved Form When Submitted
Accident Pressure
Pressure Did Not Exceed Maop
Pressure Restriction Ind
No
Upstream Valve Type Ind
Remotely Controlled
Downstream Valve Type Ind
Automatic
Length Segment Isolated
87968
Internal Inspection Ind
No
Other Restrictions Ind
Yes
Operation Complications Ind
No
Pipeline Function
Transmission System
Scada In Place Ind
Yes
Scada Operating Ind
Yes
Scada Functional Ind
Yes
Scada Detection Ind
No
Scada Conf Ind
No
Accident Identifier
Local Operating Personnel, Including Contractors
Operator Type
Operator Employee
Investigation Status
No, the operator did not find that an investigation of the controller(s) actions or control room issues was necessary due to: (provide an explanation for why the operator did not investigate)
Investigation Status Details
No unusual or abnormal operating conditions contributed to the incident
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Material Failure Of Pipe Or Weld
Cause Details
Design-, Construction-, Installation-, Or Fabrication-Related
Pwjf Failure Type
Design-, Construction-, Installation-, Or Fabrication-Related
Field Exam Ind
Yes
Fatigue Vibr Related
Yes
Failure Subtype
Mechanical Vibration
Additional Crack Ind
Yes
Additional Lack Fusion Ind
Yes
Collected Data Ind
No
Has Hydrtst Conduc Before Ind
No
Direct Asmnt Conducted
No
Non Destructive Exam Ind
No
Preparer Name
M****** R* L********
Preparer Telephone
313-389-7762
Authorizer Name
R***** H* F*********
Authorizer Telephone
313-389-7755
Narrative
Leak discovered during routine facility checks by employees of operator and employees of another operator with facilities at same location. Potential likely causations (including failures in valve body bleed or grease/sealant line extension piping) investigated, but could not be confirmed. Decision made to isolate and reduce pressure in pipeline segment to allow further investigation. After isolating 2 adjacent valve sections and reducing pressure though flow to lower pressure system, impacted segment further isolated and remaining gas vented to atmosphere. Impacted segment was purged (gas to air) using air movers in anticipation of necessity to perform welding operations to complete repairs. Investigation through excavation revealed crack in 2 inch fillet weld at socket welded connection installed in 2007 as facility modification to allow liquid removal from low point in a non-piggable section of station piping. Ice from freezing of ground water in vicinity of leak (due to cooling of gas as a result of pressure reduction) impacted adjacent 2 inch piping (not related to siphon), prompting repairs to adjacent (nonleaking) 2 inch piping in addition to piping at location of leak. After repairs were completed and nondestructive inspections completed, line segment was purged (air to gas), pressurized and returned to normal operation.
Report Received Date 2011-03-25 00:00:00
Iyear 2011
Report Number 20110033
Supplemental Number 15254
Report Type Supplemental Final
Operator Id 12408 PHMSA Enforcement
Name Michigan Consolidated Gas Co (Michcon)
Operator Street Address One Energy Plaza
Operator City Name Detroit
Operator State Abbreviation MI
Operator Postal Code 48226
Local Datetime 2011-02-23 11:12:00
Location Latitude 42.7870347 Google Maps OpenStreetMap
Location Longitude -82.5285857 Google Maps OpenStreetMap
Nrc Rpt Num 968441 NRC Report How to search
Nrc Rpt Datetime 2011-02-24 14:10:00
Commodity Released Type Natural Gas
Unintentional Release 6013
Intentional Release 5049
Accompanying Liquid 0
Fatality Ind No
Fatal 0
Injury Ind No
Injure 0
Shutdown Due Accident Ind Yes
Shutdown Datetime 2011-02-25 12:00:00
Restart Datetime 2011-02-26 23:00:00
Ignite Ind No
Explode Ind No
Num Pub Evacuated 0
Incident Identified Datetime 2011-02-24 12:57:00
On Site Datetime 2011-02-24 12:57:00
On Off Shore Onshore
Onshore State Abbreviation Mi
Onshore Postal Code 48054
Onshore City Name China
Onshore County Name St. Clair
Designated Location Milepost
Designated Name 59.00
Pipe Fac Name Belle River Mills Compressor Station
Segment Name 36" Milford-Belle River Loop
Federal No
Location Type Operator-Controlled Property
Incident Area Type Underground
Incident Area Subtype Under Soil
Depth Of Cover 105
Crossing No
Pipe Facility Type Interstate
System Part Involved Onshore Pipeline, Including Valve Sites
Item Involved Weld/fusion, Including Heat-Affected Zone
Weld Subtype Fillet Weld
Installation Year 2007
Material Involved Carbon Steel
Release Type Leak
Leak Type Crack
Class Location Type Class 2 Location
Could Be Hca No
Pir Radius 52
Heat Damage Ind No
Non Heat Damage Ind No
Hca Fatalities Ind No
Est Cost Oper Paid 0
Est Cost Unintentional Release 38500
Est Cost Intentional Release 32300
Est Cost Prop Damage 79507
Est Cost Emergency 0
Est Cost Other 0
Prpty 150307
Accident Psig 775
Mop Psig 1000
Mop Cfr Section Not On Omb-Approved Form When Submitted View CFR 49 §192
Accident Pressure Pressure Did Not Exceed Maop
Pressure Restriction Ind No
Upstream Valve Type Ind Remotely Controlled
Downstream Valve Type Ind Automatic
Length Segment Isolated 87968
Internal Inspection Ind No
Other Restrictions Ind Yes
Operation Complications Ind No
Pipeline Function Transmission System
Scada In Place Ind Yes
Scada Operating Ind Yes
Scada Functional Ind Yes
Scada Detection Ind No
Scada Conf Ind No
Accident Identifier Local Operating Personnel, Including Contractors
Operator Type Operator Employee
Investigation Status No, the operator did not find that an investigation of the controller(s) actions or control room issues was necessary due to: (provide an explanation for why the operator did not investigate)
Investigation Status Details No unusual or abnormal operating conditions contributed to the incident
Employee Drug Test Ind No
Contractor Drug Test Ind No
Cause Material Failure Of Pipe Or Weld
Cause Details Design-, Construction-, Installation-, Or Fabrication-Related
Pwjf Failure Type Design-, Construction-, Installation-, Or Fabrication-Related
Field Exam Ind Yes
Fatigue Vibr Related Yes
Failure Subtype Mechanical Vibration
Additional Crack Ind Yes
Additional Lack Fusion Ind Yes
Collected Data Ind No
Has Hydrtst Conduc Before Ind No
Direct Asmnt Conducted No
Non Destructive Exam Ind No
Preparer Name M****** R* L********
Preparer Telephone 313-389-7762
Authorizer Name R***** H* F*********
Authorizer Telephone 313-389-7755
Narrative Leak discovered during routine facility checks by employees of operator and employees of another operator with facilities at same location. Potential likely causations (including failures in valve body bleed or grease/sealant line extension piping) investigated, but could not be confirmed. Decision made to isolate and reduce pressure in pipeline segment to allow further investigation. After isolating 2 adjacent valve sections and reducing pressure though flow to lower pressure system, impacted segment further isolated and remaining gas vented to atmosphere. Impacted segment was purged (gas to air) using air movers in anticipation of necessity to perform welding operations to complete repairs. Investigation through excavation revealed crack in 2 inch fillet weld at socket welded connection installed in 2007 as facility modification to allow liquid removal from low point in a non-piggable section of station piping. Ice from freezing of ground water in vicinity of leak (due to cooling of gas as a result of pressure reduction) impacted adjacent 2 inch piping (not related to siphon), prompting repairs to adjacent (nonleaking) 2 inch piping in addition to piping at location of leak. After repairs were completed and nondestructive inspections completed, line segment was purged (air to gas), pressurized and returned to normal operation.

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